Power Ramping for Rach

1. A method of operating a secondary station for requesting access to a resource from a primary station, said method comprising: a secondary station transmitting to a primary station an access preamble to request access to a resource, upon an indication of failure of reception by the primary station of the access preamble, the secondary station starting a first power ramping scheme for transmitting the first access preamble, whereby the first power ramping scheme successively transmits one or more times the first access preamble with successive transmissions increased in power by a predetermined first power level step, upon an indication of one or more failures of reception of the first access preamble with the first power ramping scheme at the primary station, the secondary station terminating the first power ramping scheme and starting a second power ramping scheme for transmitting a second access preamble to request access to the resource from the primary station, the second preamble being different from the first access preamble, whereby the second power ramping scheme successively transmits a second access preamble with a transmission power successively increased by a predetermined second power level step being different from the first power level step of the first power ramping scheme.

2. The method of claim 1 , wherein the first power ramping scheme comprises starting from a first power level, and wherein the second power ramping scheme comprises starting from a second power level being higher than the first power level.

3. The method of claim 2 , wherein the second power level equals the power level of the last transmission according to the first ramping power scheme.

4. The method of claim 1 , wherein the use or non-use of the second power ramping scheme depends on at least one factor of the following: a signaled instruction; the first access preamble; the type of access request; the type of resource for which access is requested; one or more characteristics of the data or transmissions to follow access request.

5. The method of claim 4 , wherein at least one factor determining the use or non-use of the second power ramping scheme is signaled to the secondary station by the primary station.

6. A secondary station comprising: a processor configured to, transmit a first access preamble to a primary station to request access to a resource, said processor being further configured to, upon an indication of failure of reception of the first access preamble, at the primary station, start a first power ramping scheme for transmitting one or more times the first access preamble successively with a transmission power increased by a predetermined first power level step, and, upon an indication of one or more failures of reception of the first access preamble with the first power ramping scheme, terminating the first power ramping scheme and starting a second power ramping scheme for successively transmitting one or more times a second access preamble, that is different than the first access preamble, the second power ramping scheme transmission power increased at successive transmissions by a predetermined second power level step being different from the first power level step of the first power ramping scheme.

7. A secondary station for use in a network of one or more primary and multiple secondary stations, the secondary station comprising: one or more antennas, a coupler connected to the one or more antennas to, at alternate times, rout transmissions to the antennas and rout receptions from the antennas, a transmitter with an input and an output, the output being connected to the coupler to transmit the transmissions, a receiver with an output and an input, the input being connected to the coupler to receive the receptions, and a processor connected to the input of the transmitter and the output of the receiver to control the transmitter and the receiver for communicating with the primary station, and wherein the secondary station transmits a first access preamble to a primary station, and upon indication of one or more failures of reception of the first access preamble, the secondary station starting a first power ramping scheme for successively transmitting the first access preamble at power levels increasing by a first power level step, and upon an indication of one or more failures of reception of the first access preamble with the first power ramping scheme, terminating the first power ramping scheme and starting a second power ramping scheme, being different from the first power ramping scheme, and successively transmitting a second access preamble at power levels increasing by a second power level step different from the first power level step of the first power ramping scheme.